Zero-field remote detection of NMR with a microfabricated atomic magnetometer

We demonstrate remote detection of nuclear magnetic resonance (NMR) with a microchip sensor consisting of a microfluidic channel and a microfabricated vapor cell (the heart of an atomic magnetometer). Detection occurs at zero magnetic field, which allows operation of the magnetometer in the spin-exchange relaxation-free (SERF) regime and increases the proximity of sensor and sample by eliminating the need for a solenoid to create a leading field. We achieve pulsed NMR linewidths of 26 Hz, limited, we believe, by the residence time and flow dispersion in the encoding region. In a fully optimized system, we estimate that for 1 s of integration, 7 x 10(13) protons in a volume of 1 mm(3), prepolarized in a 10-kG field, can be detected with a signal-to-noise ratio of approximately 3. This level of sensitivity is competitive with that demonstrated by microcoils in 100-kG magnetic fields, without requiring superconducting magnets.     

精氨酸加压素对实验性神经细胞M受体位点数影响的研究

目的 观察精氨酸加压素(AVP)对实验性神经细胞M受体位点数的影响。方法 采用小鼠神经母细胞瘤细胞(NBA_2)无血清培养建立神经细胞老比实验研究模型。以M受体放射性配基分析术研究AVP对实验性神经细胞的M受体位点数的影响。结果 两种不同浓度的AVP皆可使M受体位点数下降(P<0.01),以高浓度组更著。结论 结合以前研究结果,提示AVP使M受体位点数下降的作用可能是其延缓实验性神经细胞老化的机制之一。     

Fly motion vision is based on Reichardt detectors regardless of the signal-to-noise ratio

The computational structure of an optimal motion detector was proposed to depend on the signal-to-noise ratio (SNR) of the stimulus: At low SNR, the optimal motion detector should be a correlation or "Reichardt" type, whereas at high SNR, the detector would employ a gradient scheme [Potters, M. & Bialek, W. (1994) J. Physiol. (Paris) 4, 1755-1775]. Although a large body of experiments supports the Reichardt detector as the processing scheme leading to direction selectivity in fly motion vision, in most of these studies the SNR was rather low. We therefore reinvestigated the question over a much larger SNR range. Using 2-photon microscopy, we found that local dendritic [Ca(2+)] modulations, which are characteristic of Reichardt detectors, occur in response to drifting gratings over a wide range of luminance levels and contrasts. We also explored, as another fingerprint of Reichardt detectors, the dependence of the velocity optimum on the pattern wavelength. Again, we found Reichardt-typical behavior throughout the whole luminance and contrast range tested. Our results, therefore, provide strong evidence that only a single elementary processing scheme is used in fly motion vision.     

运动神经元病患者认知功能筛查

目的 调查中国运动神经元病患者认知功能异常及额颞叶功能异常的发生情况.方法 对100例运动神经元病的患者行简易智能状态量表(MMSE),神经精神科问卷,汉密尔顿抑郁量表及汉密尔顿焦虑量表检查.并调查患者一般资料及功能等级评分(FRS)等情况.结果 MMSE结果示轻度认知障碍者占24.2%,MMSE正常与异常之间比较FRS总分及抑郁情况,两者差异有统计学意义.抗抑郁治疗3个月后随访,发现2例患者可能存在额颞叶功能受损.结论 运动神经元病患者认知功能可能轻度受损,部分存在精神行为表现异常,2例患者可能有额颞叶功能受损.     

胆囊收缩素对实验性神经细胞老化过程中微突起影响的超微结构研究

目的　探讨胆囊收缩素 (CCK8)对实验性神经细胞老化过程中细胞微突起超微结构的影响。方法　采用 NBA2 细胞无血清培养建立神经细胞老化实验模型。以扫描电子显微镜观察的细胞表面结节状物的大小以及微突起数目作为细胞老化指标 ,观察 CCK8对细胞老化过程的影响。结果　 1使细胞表面结节状物变小。 2增加细胞突起终末的微突起数量。结论　 CCK8可以延缓实验性神经细胞的老化进程值得进一步研究。     

迟发性神经元坏死过程中白介素β转化酶mRNA转录水平动态变化研究

目的探讨白细胞介素β-转化酶(ICE)在实验性血管性痴呆小鼠迟发性神经元坏死过程中额叶皮层及海马区转录水平变化.方法利用血管性痴呆模型,RT-PCR技术检测全脑重复缺血再灌(IR)后ICE mRNA的表达.结果额叶皮层重复缺血再罐注3 h时ICE mRNA表达增多,6 h后呈下降趋势,再灌注14 d时再次形成高峰.海马区神经细胞转录水平略迟于皮层,3 h已有较高表达,7 d达高峰,28 d下降至对照组水平.结论在细胞凋亡与迟发性神经元坏死发生、发展过程中,ICE伴随着全过程,ICE mRNA表达的增多使细胞凋亡增加.     

Pigmented neuron/non-pigmented neuron ratio of the substantia nigra in relation to ageing and pathological conditions

Based on 45 normal cases aged from 32 to 106 years of age, a morphometric study revealed that, despite decrease in the number of both pigmented neurons (PN) and the non-pigmented neurons (NN) with advancing age, the ratio (PN/NN) did not change (4.8). It is well-known that both the substantia nigra and the striatum send fibers to each other. McGee demonstrated that the ratio of the number of large neurons to that of small neurons was constant, irrespective of different ages, although number of both neurons decreased with ageing. It was therefore apparent that this phenomenon in the putamen was the same as in the substantia nigra. It could be considered that "balanced depopulation of different neurons" in the nucleus of the strio-nigral circuit contribute to support normal extrapyramidal functions. Additionally, the centenarian cases showed larger numbers of both PN and NN than younger case. It was likely that they could be classified as so-called "excellent" centenarians. On the other hand, idiopathic Parkinson's disease (15 cases) showed that while the same number of NN remained as in age-matched controls, PN showed marked depopulation. Olivopontocerebellar atrophy of the sporadic type (OPCA, 10 cases) and progressive supranuclear palsy (PSP, 5 cases) showed a decrease in number of both PN and NN. However, NN in PSP showed much more decrease than OPCA. NN sends fibers to the pontine tegmentum as well as the thalamus, and PSP shows marked atrophy of the brainstem tegmentum. In this connection, it was considered that marked decrease of NN in PSP could be related to tegmental atrophy.     

周期蛋白D1与脑缺血神经元程序性死亡

脑局部缺血后神经元损伤除通常认为的坏死外 ,还存在程序性细胞死亡。而在这一过程中 ,周期蛋白D1可能发挥了重要的作用。     

Point process modelling of the Afghan War Diary

Modern conflicts are characterized by an ever increasing use of information and sensing technology, resulting in vast amounts of high resolution data. Modelling and prediction of conflict, however, remain challenging tasks due to the heterogeneous and dynamic nature of the data typically available. Here we propose the use of dynamic spatiotemporal modelling tools for the identification of complex underlying processes in conflict, such as diffusion, relocation, heterogeneous escalation, and volatility. Using ideas from statistics, signal processing, and ecology, we provide a predictive framework able to assimilate data and give confidence estimates on the predictions. We demonstrate our methods on the WikiLeaks Afghan War Diary. Our results show that the approach allows deeper insights into conflict dynamics and allows a strikingly statistically accurate forward prediction of armed opposition group activity in 2010, based solely on data from previous years.     

全脑缺血再灌注小鼠额叶、海马区神经元损伤的病理研究

目的 探讨全脑缺血再灌注小鼠中枢神经细胞损伤情况。方法 采用重复阻断小鼠双侧颈总动脉并尾部放血（放血量小于体重的6％）再灌注的方式，建立了小鼠卒中模型。在此模型基础上，采用病理学技术，对脑缺血再灌注后小鼠额叶、海马区脑组织形态变化变化进行观察。结果 重复缺血再灌注1d神经细胞间质水肿，胞核浓染、固缩，再灌注3d，额叶皮层少量胶质细胞增生；海马可见颗粒细胞呈空泡样变性。缺血再灌注7d，皮层多量的小胶质细胞增生聚集成堆；海马CA1区锥体细胞变性，且部分坏死。缺血再灌注28d，皮层神经细胞明显减少；海马CA1、CA3区锥体细胞大量缺失、变性、坏死，齿状回颗粒细胞变性呈空泡样。结论 脑缺血再灌流中存在迟发性神经元死亡。     

术前白蛋白与碱性磷酸酶比值作为食管癌患者诊断指标的临床价值

目的探讨术前白蛋白与碱性磷酸酶比值(albumin-to-alkaline phosphatase ratio,AAPR)对食管癌的诊断价值。方法选取2018年1月至2020年10月于我院胸外科行食管癌根治术的患者202例,同时期于我院消化内科住院治疗的食管良性疾病患者215例和胃镜检查未见明显异常的体检者214名,比较三组患者的AAPR、纤维蛋白原与前白蛋白比值(fibrinogen to pre-albumin ratio,FPR)、中性粒细胞与淋巴细胞比值(neutrophil to lymphocyte ratio,NLR)、癌胚抗原(carcinoembryonic antigen,CEA)、糖类抗原19-9(carbohydrate antigen 19-9,CA19-9)的水平,利用ROC曲线评价AAPR、FPR、NLR、CEA、CA19-9对食管癌患者的诊断及良恶性患者的鉴别诊断;利用Logistic回归分析食管癌良恶性鉴别诊断的危险因素。通过Kruskal-Wallis H检验、Mann-Whitney U检验AAPR、FPR、NLR与食管癌患者临床病理特征的相关性。结果食管癌组患者术前AAPR显著低于食管良性疾病组、健康对照组(P<0.001),FPR、NLR、CEA、CA19-9均显著高于食管良性疾病组、健康对照组(P<0.001);FPR、NLR、CEA、CA19-9在食管良性疾病组与健康对照组中比较,差异无统计学意义(P>0.05);而AAPR在这两组患者中比较,差异有统计学意义(P<0.05);通过Kruskal-Wallis H检验、Mann-Whitney U检验对食管癌患者临床病理特征分析显示,随着淋巴结转移、浸润深度加深、肿瘤直径增加、临床分期增加,食管癌患者的AAPR的中位数显著降低,FPR的中位数显著升高,而与肿瘤部位无相关性。ROC曲线分析结果显示,AAPR对食管癌的诊断效能显著高于其他指标。Logistic回归显示,AAPR、NLR、CEA均与食管癌和食管良性疾病的鉴别诊断显著相关。在食管癌与食管良性疾病的鉴别诊断上,AAPR与其他指标联合可提高诊断效能,其中AAPR、FPR、NLR、CEA、CA19-9联合,ROC曲线下面积最大,有最大的诊断效能(AUC=0.830,灵敏度为79.2%,特异度为71.4%)。结论AAPR可能是诊断食管癌有价值的生物标志物,其与FPR、NLR、CEA、CA19-9联合可显著提高食管癌和食管良性疾病的鉴别诊断效率。     

腰臀比为非酒精性单纯性脂肪肝最有效的预测指标

非酒精性脂肪性肝病(NAFLD)如能被早期发现并及时治疗,则可阻止其进一步发展,且能使其逆转[1].因此,寻找一种简单而有效的预测NAFLD最早阶段单纯性脂肪肝发生的指标具有重要的临床意义.本研究通过检测临床与病理确诊的单纯性脂肪肝患者与肥胖相关的腰围、腰臀比、腰高比及人体质量指数(BMI)4项人体学指标,探讨预测单纯性脂肪肝最有效的人体学指标.     

Rescuing Z+ agrin splicing in Nova null mice restores synapse formation and unmasks a physiologic defect in motor neuron firing

Synapse formation at the neuromuscular junction (NMJ) requires an alternatively spliced variant of agrin (Z⁺ agrin) that is produced only by neurons. Here, we show that Nova1 and Nova2, neuron-specific splicing factors identified as targets in autoimmune motor disease, are essential regulators of Z⁺ agrin. Nova1/Nova2 double knockout mice are paralyzed and fail to cluster AChRs at the NMJ, and breeding them with transgenic mice constitutively expressing Z⁺ agrin in motor neurons rescued AChR clustering. Surprisingly, however, these rescued mice remained paralyzed, while electrophysiologic studies demonstrated that the motor axon and synapse were functional-spontaneous and evoked recordings revealed synaptic transmission and muscle contraction. These results point to a proximal defect in motor neuron firing in the absence of Nova and reveal a previously unsuspected role for RNA regulation in the physiologic activation of motor neurons.     

穴位针刺干预急性低氧大鼠肺动脉压与海马神经损伤的实验研究

目的探讨穴位针刺对急性低氧所致大鼠肺动脉压(PAP)升高与神经细胞损伤的干预作用。方法将60只SD大鼠随机平均分为正常对照组(N)、低氧组(H)、针刺+低氧组(AH)。将各组动物分别用25%乌拉坦(125 mg/100 g)腹腔麻醉,H组和AH组(放入低氧舱之前先针刺30 min)动物置于低氧舱后再吸入15%的O2,3组均测量大鼠PAP,30 min后处死。3组均测定脑含水量和大脑腺苷A1受体表达水平,并对不同组大鼠神经细胞进行形态学观察。结果 AH组PAP明显低于H组(P<0.01),但与N组相比差异无统计学意义;海马神经元形态学显示,H组神经元有明显的胞质空染、核固缩,AH组与N组神经元无明显的胞质空染、核固缩。结论穴位针刺可预防大鼠急性低氧引起的PAP升高和海马神经元损伤。     

运动神经元病与TDP-43蛋白的病理性表达

目的 认识TDP-43蛋白在运动神经元病中枢神经系统的病理性表达特征.方法 对4例经尸检病理证实的运动神经元病的临床及病理组织学特征进行总结;并对其脑和脊髓切片进行泛素、磷酸化TDP-43免疫组化染色,观察其阳性表达情况,并与同年龄、无神经疾病病史的3例病例的脑和脊髓组织进行对照.结果 4例病例具有运动神经元病典型的临床与组织学特征,其脑和脊髓组织中,3例存在神经元泛素阳性包涵体结构,主要表现为丝团样包涵体,致密圆形包涵体及路易样包涵体;2例存在明确的TDP-43阳性表达,表现为广泛分布于大脑运动皮层及脊髓前角的各种形态的神经元胞浆包涵体及胶质细胞包涵体,1例存在脊髓前角神经元TDP43弱阳性表达.对照病例无泛素阳性及TDP-43阳性包涵体发现.结论 运动神经元病患者的中枢神经系统存在广泛TDP-43蛋白阳性表达,且其阳性包涵体具有一定特征性,值得进一步研究其形成机制.     

瞬时无波形比值和定量血流分数评价冠状动脉临界病变准确性的对比研究

目的以血流储备分数(FFR)为标准,比较定量血流分数(QFR)和瞬时无波形比值(iFR)评估冠状动脉临界病变的准确性,并分析QFR与iFR的相关性及诊断一致率。方法回顾性纳入北京大学第三医院2015年5月至2020年6月因冠心病进行冠状动脉造影(CAG)并接受FFR和iFR检测的62例患者,收集患者的临床和CAG病变解剖学资料、靶血管iFR和FFR值,并测量同一靶血管的QFR值。以FFR≤0.80为判断心肌缺血的临界值,比较QFR和iFR与FFR评估冠状动脉临界病变的准确性,并分析QFR与iFR的相关性及诊断一致率。结果62例患者中,有53例(85.5%)靶血管为左前降支,基线直径狭窄率为48.0%(41.1%,55.7%)。iFR、QFR与FFR均具有较好的相关性[r=0.773(95%CI 0.649~0.857)、r=0.626(95%CI 0.445~0.757),均P<0.001]。QFR、iFR预测FFR≤0.80的受试者工作特征曲线下面积(AUC)比较,差异无统计学意义[0.859(95%CI 0.748~0.935)比0.875(95%CI 0.766~0.945),P=0.801];二者与FFR诊断一致率的差异无统计学意义(74.2%比79.0%,P=0.615)。QFR与iFR的相关性较弱(r=0.396,95%CI 0.162~0.587,P=0.0015)。QFR对应iFR≤0.89的AUC为0.663(95%CI 0.524~0.801,P=0.028)。QFR、iFR联合诊断策略可以与FFR达到88.7%的诊断一致率,同时减少58.1%的压力导丝使用。结论iFR与QFR评估冠状动脉临界病变具有相似的诊断准确率,但二者相关性较弱。二者联合诊断策略可进一步提高诊断准确率。     

碘对人胎大脑神经原特异性烯醇化酶表达的影响

利用生理剂量碘作用于早期人胎大脑神经细胞无血清培养物,经离子交换法分离出神经细胞的神经原特异性烯醇化酶(NSE)和非神经原特异性烯醇化酶(NNE)。两酶的转换方式与体内相似,碘促进神经细胞 NNE(αα,αγ亚基)向 NSE(γγ亚基)转换。培养25天 KI(?)组NSE 含量比培养30天对照组含量高,培养30天 KI_2组 NSE 含量是对照组的3倍,且 NSE 出现提前,活性增高。培养15天时加碘的作用比开始培养时加碘的作用更加明显。     

Neutrophil-lymphocyte ratio is useful for the prognosis of patients with hepatocellular carcinoma

There is increasing evidence that neutrophil-lymphocyte ratio (NLR) may play a role in predicting recurrence in patients with hepatitis B virus-related hepatocellular carcinoma (HCC) after liver transplantation. In the original study by Yan et al, it was aimed to determine whether an elevated NLR is associated with tumor recurrence. Total tumor size (> 9 cm) and macro-vascular invasion were found to be more significant than NLR according to the multivariate logistic regression analysis. Therefore, substantive significance should be emphasized rather than NLR because total tumor size and macro-vascular invasion are easier and more expressive than NLR in assessing HCC recurrence. NLR and platelet-lymphocyte ratio (PLR) are markers which are easy to obtain and can be used as inflammation indicators. Moreover, assessment of both NLR and PLR may add some value as a good predictor of risk for post-liver transplantation HCC recurrence. However, while the study was constructed on whole blood analysis, further details about the features and performance characteristics of the whole-blood analyzer, and preanalytical/analytical variables should also be mentioned.